Consolidated Balance Sheets (Current Period Unaudited) (Parentheticals) - USD ($)	Dec. 31, 2020	Sep. 30, 2020
Statement of Financial Position [Abstract]
Allowance for doubtful accounts	$ 250,000	$ 250,000
Allowance for excess and obsolete inventory	$ 3,054,000	$ 3,054,000
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	30,000,000	30,000,000
Common stock, shares issued (in shares)	12,366,593	11,822,009
Common stock, shares outstanding (in shares)	12,366,593	11,822,009